From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Deegan Subject: Re: [PATCH 1 of 2 RFC] xen, pod: Zero-check recently populated pages (checklast) Date: Thu, 14 Jun 2012 10:07:25 +0100 Message-ID: <20120614090725.GC82539@ocelot.phlegethon.org> References: <4145b32d0c43d7d46650.1339155932@exile> <4FD205E80200007800088C36@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <4FD205E80200007800088C36@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: george.dunlap@eu.citrix.com, xen-devel List-Id: xen-devel@lists.xenproject.org At 13:02 +0100 on 08 Jun (1339160536), Jan Beulich wrote: > >>> On 08.06.12 at 13:45, George Dunlap wrote: > > --- a/xen/include/asm-x86/p2m.h > > +++ b/xen/include/asm-x86/p2m.h > > @@ -287,6 +287,9 @@ struct p2m_domain { > > unsigned reclaim_super; /* Last gpfn of a scan */ > > unsigned reclaim_single; /* Last gpfn of a scan */ > > unsigned max_guest; /* gpfn of max guest demand-populate */ > > +#define POD_HISTORY_MAX 128 > > + unsigned last_populated[POD_HISTORY_MAX]; /* gpfn of last guest page demand-populated */ This is the gpfns of the last 128 order-9 superpages populated, right? Also, this line is >80 columns - I think I saw a few others in this series. > unsigned long? > > Also, wouldn't it be better to allocate this table dynamically, at > once allowing its size to scale with the number of vCPU-s in the > guest? You could even make it a small per-vcpu array, assuming that the parallel scrubbing will be symmetric across vcpus. Cheers, Tim.